Serena Williams has bared all to show off her pregnancy in a daring cover shoot for the August issue of Vanity Fair magazine.

The cover, shot by renowned photographer Annie Leibovitz and unveiled Wednesday morning (AEST), features the tennis star in profile with her right arm covering her breasts and her pregnant stomach prominently on display. 

The 35-year-old Williams announced her pregnancy with Reddit co-founder Alexis Olhanian in April when she posted a Snapchat photo of herself with the caption “20 weeks”.

Vanity Fair reports the couple will be married the later this year, after the baby is born.

Williams told the magazine she “did a double take” and her heart “dropped” when she saw a positive test because it came just before the Australian Open, which she won.

Check out my Vanity Fair Cover. Question- what do u guys think boy or girl? I'm waiting to find out but would love to hear your thoughts. pic.twitter.com/Nnq4VKCu8N

— Serena Williams (@serenawilliams) June 27, 2017

“If you would have told me last year in October or November that I would have a baby, not be pregnant but have a baby, I would have thought you were the biggest liar in the world,” Williams told Vanity Fair.

“This is kind of how I am right now. This is happening sooner than later, and it’s going by so fast.”

Williams shared the Vanity Fair cover on Twitter and invited followers to guess whether she was having a boy or girl, despite earlier reports claiming she was expecting a girl.

“I’m waiting to find out but would love to hear your thoughts,” she said.

The cover was released the same day John McEnroe refused to apologise for saying 23-time grand glam singles winner Williams would be ranked around 700th in the world if she played in men’s tennis.

“Maybe at some [sports], a woman can be better than anybody. But I haven’t seen it in any other sport, and I haven’t seen it in tennis,” McEnroe said

Williams responded quickly on Twitter saying: Dear John, I adore and respect you but please please keep me out of your statements that are not factually based.”

“I’ve never played anyone ranked ‘there’ nor do I have time.

“Respect me and my privacy as I’m trying to have a baby. Good day sir.”

Williams plans to sit out the rest of the 2017 season and return to competition in January 2018.